The couple will hold their festivities in New Orleans during a ceremony that will cost $1 million. Some of the guests who are expected to be in attendance include Beyonce, Jay-Z, Kris Jenner, Ciara and Prince Harry's girlfriend Meghan Markle.

"Serena and Alexis chose the Contemporary Arts Center because of its incredible architecture and history," a source told the website. "They have instructed Preston to fill the hall with thousands of dollars worth of crystals and flowers. The hall will be totally transformed."

Williams and Ohanian announced their engagement in December and Williams gave birth to her first daughter in September.